Crown-mounted porcelain-facing element



June 23, 1925. 1,543,421

. H. A. COTTLER RQWN MOUNTED PORCELAIN FACING ELEMENT Filed Sept. 26. 1924 Patented June 23, 1925.

PATENT OFFICE.

HAROLD A. COTTLER,OF BROOKLYN, NEW YORK.

CROWN-MOUNTED PORCELAIN-FACING ELEMENT.

Application filed September 26, 1924. Serial No. 739,978.

To all whom it may concern."

. Be it known that I, HAR LD A. CoT'rLER,

a citizen of the United States, and a resident of the borough of Brooklyn, county of Kings, city and State of New York, have 1 invented-certain new anduseful Improvements in Crown-Moui1ted Porcelain-Facing Elements, set forth in the following specification.

This invention relates to artificial teeth. Its object is to make possible the crowning of a natural tooth with a minimum amount of preparation of the natural tooth permitting the use of a completely enclosing metal crown and, at the same time, providing for a labial facing of enamel-like ma terial simulating the appearance of a natural tooth. I

More specifically, it is an object of-the invention, in addition to the general object recited, to'iinprove the means and method of fitting the facing to the crown, adjusting and adapting it to the gum line and gum contour firmly anchoring it to the crown and, at the same time, minimizing, if not substantially eliminating, all visibility of the metal portion of said crown.

Heretofore, combined metal crowns and facings have been fabricated in such a way that the facing constituted a panel made accurately to fit within a completely enveloping flange extending around all four sides of the panel and adapted to be burnished over to hold'the panel in place. 7

. More particularly, it is the object of my invention to overcome the disadvantages requiring the facing to be shaped to fit into a virtual socket embracing all its four edges. An object also is toprovide for lengthwise adjustment of the facing without tedious and expensive alteration of the facing itself and without any alteration of the metal crown.

Still further objects of the invention are to improve the detail construction of ainetal tooth crown and the adaptation thereto of 1 alabial finished facing, all of which objects will better be understood by reference to the illustrative embodiment of my invention described in the following specification and shown in the accompanying drawings which form a part of my specification. It is to this illustrative embodiment that my claims are directed merely for purposes of illustration and not limitation.

In the drawings, Figure 1 is a diagrammatic labial view with the gum line and rootindicated in dot and dash lines with the preferred finished construction embodying my invention;

Fig. 2 is a similar view with the finished facing removed, but with its edge shown in dot and dash lines;

Fig. 3' is a labial vertical cross section;

Fig. 4 is a horizontal cross section through the plane of line IVIV of Figure 3; and

Fig. 5 is a perspective view of the crown ready for the insertion and mounting of the facing, but with the facing omitted.

A metal crown A is fabricated according to any approved method'to fit about and conform to the size and contour of the natural tooth to be crowned, the preparation of the natural tooth, of course, providing for the proper positioning of the biting edge key. It is necessary that the metal structure of the crown A be sufiiciently rigid and strong to withstand. the outward stresses upon the flanges 1 and Qoccasioned by the forcible contacttherewith' of the facing B.

This is best accomplished by casting the,

crown A from the usual gold alloy, but casting it as an entirety with the flanges and all of its other integral parts of the structure. processes known in the art after first forming a suitable model in wax. Although I have shown the keyway overlying one wall 4 forming an integral part of the tooth crown A and functioning in the structure illustrated as a tensionmember, tending to resist separation of the flanges 1 and 2, it is not vessential to my invention that the metal crown structure actually extend across from flange to flange. It may be perforated or omitted. But in the preferred embodi- .ment of my invention, the cross wall i is present. Preferably, the undercutflanges 1 and 2 taper towards each other away from This is readily accomplished by 'ferred embodiment of my'invention, the tapered positioningof theflanges positively alone upon the cement.

and that it be provided along, its side edges with bevels 7 and 8 complementary to the undercutting of the flanges 1 and 2, and, of course, parallel therewith. The crown A'is properly mounted upon the prepared natural tooth and cemented in place. The partially prepared facing B may then be forced down through the incisal edge of the crown between the flanges land 2-so that its bottom end or edge 9 may be studied with relation to the gum contour and so that its entire appearance relatively to the other tooth may be studied. It may then readily be slipped-outand altered in itsconfigurationto conform to the ideas of-the surgeon. Again,

it is slipped into the lteyway. One great advantage of my invention vis that this facing 13 may, during the course of its fabrication, be tested again and again in the actual position in which it is to be Worn. Of course, it .is preferable, before this personal fitting takes place that its under face 10 be shaped concavely to lit the convex wall 1, whether this wall t be the metal wall tor the face .of the patients natural tooth. After the size and configurationof the facing-Bhas been determined, completely, its incisal edge 11 should be finished off and this facing is then permanently seated in the l eyway5 with a suitable cementat'ious material applied both to the wall 4; and to therear face 10 of the facing B. A'film or layer 12 ofsuch cement between the wall 4 andthe facing IB serves to aid inholding the facing mounted onthe crown, butin accordance with my invention, the mounting ofthis facing is not dependent 1, preferably provide an outstandingedge or lip-13alongthe incisal edge 5 of the metal crown, which,

during the fitting of: the facing, clears the key'way 3 tov leave the same unobstructed 'for the entrance of the faci11g,-,lout afterthe facing has been finished and permanently inserted, I burnish or swage this lip 13 over the incisal edge of the cementatious layer 12 as indicated in Figure 3, which protects the facing B at the locality of greatest wear and prevents the forcing into the crackzbetween the facing and the crown of foreign matter.

In addition to this, however, inthe prelocks'the facing against movement responsive to incisal pressure." In other words, the position of these flanges is such as to exert a component of reactive force in opposition to all force coming from an incisal direction.

It is preferred that the positioning of the flanges 1 and 2 correspond as nearly as possible with the lateral profile limits of the crown B and it has been found in the actual shaping of the facing B that it may slightly bulge so that a front View of the tooth virtually shows no metal as indicated in Figure 1. It is also to be noted that the unrestricted opening at the gum end of the keyway readily permits the positioning of the facing B so that it may extend and actually be fitted into a position below the gumline, although, of course, this positioning is not essential to my invention and it is nota necessity that the facing be actually forced below the gum line. According to one good practice the facing at 1ts gum edge s shaped v accurately to fit the gum contour without penetration but with such close contact as to give the appearance 'of-a natural tooth.

The inventive thought may have a variety of expressions, as is'contemplated'by what I claim and desire to secure by United States Letters Patent asfollows: V

'1. In artificial teeth, ametal crown adapted closely to embrace and encloseaprepared natural tooth, the labial portion of'said ]age of said facing by said flanges-exerts a 1'6-2LC13111g component of force aga nst inclsal forces.

3. The structure as described in claim 1 andfurther characterized by the factythat a protective'lip1 is provided along the incisal entrance into said keyway which is capable of beingburnished over asa protective cov- 'ering for the parting space'betweensaid crown and the incisal edge of 'saidfacing.

In witness whereof, 1' have signed my name to this specification thisl lth dayof August, 1924;. V

HAROLD A. COTTLER. 

